1. Field of Invention
The present invention relates to a sensor equipped alarm device. More particularly, the present invention relates to a portable, internally powered and sensor-equipped alarm device that can be mounted anywhere.
2. Description of Related Art
A conventional security alarm system contains power circuits, sensors, amplifier circuits, warning sound and flashing light control circuits, all of which must be individually designed. FIG. 1 is a block diagram showing the component parts of a conventional security alarm system. As shown in FIG. 1, the system includes a sensor 2, an amplifier 4, a power circuit 6, an alarm generator 8 and an alarm-reporting device 10. First, information regarding any changes in the external environment is fed to the sensor 2. For example, the sensor 2 can be an infrared sensor, which constantly samples infrared signals from its surrounding space. Next, the signals are sent to the alarm generator 8 via the amplifier 4. Finally, the alarm-reporting device 10 picks up warning signals from the alarm generator 8 and informs the user about the current situation. The alarm reporting device 10 can be a buzzer or a light emitting diode (LED), for example. Furthermore, an external power source enters the system via the power circuit 6 and supplies electrical power to the sensor 2, the amplifier 4 and the alarm generator 8.
Each component in the above security alarm system has to be individually designed. Moreover, once the system is designed, it is very difficult to select other sensors or alarm devices more appropriate for the situation. In addition, an external power source must always be nearby and the system will be activated as soon as the power is switched on. Therefore, the system is difficult to install and is particularly wasteful when the security alarm system is needed only for short periods of time.
In light of the foregoing, there is a need to provide a portable and flexible alarm device.